This invention relates generally to tiled displays.
Tiled displays may be made up of a plurality of display modules integrated by a plate such as a glass plate. Thus, the overall display image may be made up of subimages created by each of the display modules. By coordinating the display of subimages on each module, an overall coherent image may be generated.
Each of the individual modules may include a large number of pixels which are driven by drivers generally located remotely from those pixels. Because the tiled displays are generally made of material incompatible with logic devices, such as display drivers, the display drivers are formed in a surface separate from the actual display elements. This spacing of course adds to the complexity of the overall tiled display. The greater distance between the driver and the display may also adversely effect the speed of the display. Moreover, the need to interconnect the pixel elements with the drivers may increase the cost of the overall display.
Commonly, logic elements such as display drivers are formed of complementary metal oxide semiconductor (CMOS) integrated circuits. These devices can be fabricated at low cost through high volume manufacturing procedures. In addition, the resulting devices are of extremely small size. Thus, the use of the CMOS integrated circuit fabrication techniques is generally preferred for making all types of logic devices including display drivers.
However, because of the basic incompatibility between the CMOS substrates and the substrates that are utilized in most display devices, a separate back plane must be provided on the display for mounting CMOS integrated circuits. These integrated circuits may then be connected from the back plane to the individual pixels or display elements. As mentioned above, this may result in reduced speed, increased cost, and overall complexity.
Some tiled displays use emissive display elements such as organic light emitting diodes. These displays use a passive matrix to drive the individual pixels. This has the advantage of reducing the cost, in particular the capital cost of the manufacturing infrastructure. However, a passive matrix drive (which is a form of multiplexing) puts extra demands on the emissive materials. When multiplexed, such materials are less efficient and have more reliability problems than when operated continuously.
Thus, there is a need for a way to make tiled displays in which the display drivers can be integrated into a display substrate.